Fan structure



A. S. HOWELL Feb. 14, 1933.

FAN STRUCTURE Filed Nov. 10, 1 928 3 Sheets-Sheet 1 Feb. 14, 1933.

FAN STRUCTURE Filed Nov. 10, 1928 3 Sheets-Sheet 2 47" M WM,

A. s. HOWELL 1,897,947

Feb. 14, 1933. HOWELL -1,897,947

FAN STRUCTURE Filed Nov. 10, 1928 sheets $heet s 3/ L I v a 33 I 9 /k% wQ .zzay'.

Patented ream, 1933 UNITED STATES PATENT OFFICE ALBERT S. HOWELL, OFCHIC-AGO, ILLINOIS, ASSIGNOR TO THE BELL & HOWELL COM- Pm, OF CHICAGO,ILLINOIS, A CORPORATION OF ILLINOIS FAN STRUCTURE A lication filedNovember 10, 1928. Serial No. 818,460.

My invention has particular relation to centrifugal fans such as areused in motion picture projecting machines although not limited to thisuse alone.

The main object of the invention resides in the provision of anefiective fan structure, the impelling. structure of which is formed ofsuitable sheet material, such as sheet metal, all with a view towardlightness, uniformity and adaptability to quantity production, and whichcauses comparatively little noise in operation and which is adapted foruse on motion picture projecting machines for cooling purposes.

lVith this object in view my invention consists in certain features ofnovelty in the construction, combination and arrangement of parts bwhich the said'object and certain other 0 jects, hereinafter appearing,are effected, all as fully described with reference to the accompanyingdrawings and more articularly pointed out in the appended claims.

In the said drawings I Figure 1 is a front elevation of a motion pictureprojecting machine embodying my invention;

Figure 2 is an enlarged partial plan view of the same with parts brokenaway and shown in section;

' Figure 3 is a section on the line 33 of Figure 2 with parts brokenaway Figure 4 is a partial perspective view of the fan. structure of myinvention with parts broken away an'd in section;

Fi re 5 is an enlarged partial section on the line 5-5 of Figure 1; and

Figure 6 is a perspective view of one of the balancin elements of myinvention.

Like 0 aracters of reference indicate like parts in the several views.

In the said drawings, 1 designates a composite frame which forms a motorchamber 2 and a fan chamber 3 disposed in a vertical transverse lane infront of the motor chamber. See Figures 1, 2 and 3.

motor chamber 2 on a forwardly and rearwardly extending axis, and themotor shaft 5 extends forwardly therefrom through the fan chamber 3. SeeFigure 2.

by means of which it is secured on the motor shaft.

Mounted on the carrier member 6 is the fan assembly of my inventionwhich will now be described. See Figures 2, 3, 4 and 5.

A strip of material, such as sheet metal, is bent at intervalstherealong substantially on radii of the axis of the fan to form.alternate impelling blades 8 and spacing portions 9 arranged about theaxis of the fan with sets of alternate spacing portions 9 disposed onrespective sides of the blades 8 in adjoining relation. See particularlyFigure 4.

A pair of annular sheet metal members 11 are disposed at opposite sidesof the blades 8 and engage the adjacent sets of alternate spacingportions 9. These annular members 11 are provided with tabs 12 at theinner noise caused'by the operation of the fan, and

is well adapted for quanti t production.

In addition, it will 'be 0 served that the blades of the fan consist oftwo sets of alternating blades and that one set thereof is disposeddiagonally with respect to the other set transversely of the flowbetween the blades, and preferably, as shown, each of said firstmentioned set extending from the side of one of the second mentioned setto the correspondingly opposite side of the next of said secondmentioned set, this arrangement having an effect on the backwash tolessen the noise of the fan in operation. An electric motor 4 isarranged within the The carrier member 6 is provided with a peripheralrearwardly facing shoulder 13, and the inner edge portion of one of theannular members 11 is engaged on this shoulder and the carrier member ispeaned rier member for the driving thereof by the motor 4. Seeparticularly Figure 5.

The fan is preferably, as shown, a centrifugal fan, and air is drawnthrough air openings 15 in the frame 1 into the motor chamber 2 and fromthere is drawn into the inside of the fan through an opening 16 in apartition wall between the motor chamber 2 and the fan chamber 3. Theair is expelled from the periphery of the fan into the fan chamber andis forced out of the fan chamber to perform its functions, such asthrough a passage 17 into a lamp chamber 18 of the frame 1 where itserves to prevent the lamp chamber and related parts from becomingoverheated. See Figure 2.

In order that the fan may be pro erly balanced the following isprovided. mall weights 19 of U-shape, see Figure 6, cmbrace the innerportion of the proper blades 8 and are clamped thereon, as shown inFigures 3 and 5. These weights are preferably of sheet spring metalwhich are clamped on the blades by the tension thereof, and the endedges thereof are preferably diagonally disposed in opposite relation,as designated at 21 in Figure 6, to facilitate the engagement thereofupon the blades of the fan.

The carrier member 6 has a forwardly facing annular surface 22 adjacentits periphery, the periphery of the carrier member providing acylindrical surface at the outer edge of this annular surface, and thecarrier member being provided with a forwardly facing-groove 23 at theinner end of this annular surface. See Figures 3, 4 and 5.

An annular friction member 24 of wear resisting metal, such as steel,overlies the aforementioned annular surface 22 and is provided with acylindrical flange 25 at its outer ed e engaged over the periphery ofthe mem er 6 and bent thereagainst. The member 24 is provided at itsinner edge with an offset portion 26 engaged in the groove 23 and theinner wall portion of the groove is peaned over this offset portion, asdesignated at 27 in Figure 5.

Thus is the friction member 24 securely mounted on the memberfi by meansdisposed at the inner and outer edges of the member 24 with obviousadvantage.

The construction permits of the carrier member 6 being formed ofacomparatively soft metal, such as that which is used in the manufactureof die castings, whereby this member may be so formed, thereby furtherrendering the device conducive to lightness, uniformity and quantitymanufacture.

ngaged in a recess in the front wall of fan chamber 3 is a friction shoe28, which upon rearward pressure exerted thereon is frictionally engageable with the friction member 24 fort e purpose of regulating thespeed of the mechanism. See Figures 3 and 5. r

The rearward pressure of the shoe 28 upon the friction member 24 isadjusted for adjustably controlling the speed of the mecha nism by meansof a manually actuated-screw 31 screwthreaded rearwardly into the frame1 and operating upon the shoe 28 through a my invention, but having thusdescribed my invention, I claim as new and desire to secure by LettersPatent the following:

1. In a fan the combination of a strip of material bent at spacedintervals-therealong substantially on radii of the axis of the fan toform impelling blades arranged about the axis of the fan, and means forsecuring said blades in assembly in their said arrangement.

2. In a fan the combination of a strip of material bent at spacedintervals therealong substantially on radii of the axis of the fan toform impelling blades arranged about the axis of the fan and spacingportions therebetween, and means associated with said spacing portionsfor securing said blades in assembly in their said arrangement.

. 3. In a fan the combination of a strip of material bent at spacedintervals therealong substantially on radii of the axis of the fan toform alternate impelling blades and spacing portions, and meansassociated with said spacing portions for securing said blades arrangedabout the axis of the fan withalternate spacing portions adjoining oneanother.

4;- Ina centrifugal fan the combination of a strip of material bent atspaced intervals therealong substantially on radii of the axis of thefan to form impelling blades and spacing portions therebetween, andmeans for securing said blades arranged about the axis of the fanincludingan annular member engaging said spacing portions disposed atoneside of said blades and provided with tabs, at the inner and outer edgesthereof, bent about the inner and outer edge portions of these spacingportions.

5. In a centrifugal fan the combination of a strip of material bentat'spaced intervals therealong substantially on radii of the axis of thefan to form alternate impelling blades and spacing portions arrangedabout the axis of the fan with sets of alternate spacing portionsdisposed on respective sides of said blades in adjoining relation, and apair of annular members disposed at opposite sides of said blades andengaging the adjacent spacing portions and provided with tabs, at

the inner and outer edge portions of said spacing portions.

6. In a centrifugal fan the combination of a strip of sheet metal bentat spaced intervals therealong substantially on radii of the axis of thefan to form impelling blades spaced about the axis of the fan, meansincluding an annular sheet metal member at one side of said blades forsecuring said blades in their said relation, and a revolubly mountedcarrier member on which said annular memher is secured for the mountingof the blade and annular member assembly on the carrier member. 7. In acentrifugal fan the combination of a strip of sheet metal bent at spacedintervals therealong substantially on radii ofthe axis of the fan toform impelling blades and spacing portions therebetween, meansforsecuring said blades arranged about the axis of the fan and includingan annular member engaging said spacing portions dis osed on 7 one sideof said blades and provi ed'with tabs, at the inner and outer ed esthereof, 35 bent about the inner and outer efge portions of thesespacing portions, and a revolubly mounted carrier member provided with aperipheral shoulder engaging the inner edge portion of said annularmember and peaned over the same to secure the blade and annularmemberassembly thereon. 8. In a centrifugal fan the combination of a strip ofsheet metal bent at spaced intervals therealong substantially on radiiof the axis of the fan to form alternate impelling blades and spacingportions arranged about the axis of the fan with sets of alternatespacing portions disposed on respective sides of said blades inadjoining relation, a air of 40 annular sheet metal members dispose atopposite sides of said blades and enga ing the adjacent spacing portionsand provi ed with tabs, at the inner and outer edges thereof, bent aboutthe inner and outer e ge portions of said spacing portions, and arevolubly mounted carrier member provided with a peripheral shoulderengaglng the inner edge portion of one of said annular members andpeaned over the same to secure the blade and annular member assemblythereon.

In witness whereof I hereunto afi'ix my signature this 15th,day ofOctober, 1928.

ALBERT S. HOWELL.

